1. Field of the Invention
The present invention relates to a method for manufacturing an ink jet recording head, and an ink jet recording head manufactured using such method of manufacture.
2. Related Background Art
Conventionally, as disclosed in the specification of Japanese Patent Laid-Open Application No. 55-132253, for example, an ink jet recording head is structured by bonding a first substrate, which is provided with discharge energy generating devices arranged on a silicon substrate, together with a second substrate, which is provided with the recessed portion that forms ink flow paths when bonded to the first substrate; an orifice plate conductively connected with the ink flow paths to form discharge openings for discharging ink; and the recessed portion that constitutes a common liquid chamber that provisionally retains ink to be supplied to each of the discharge openings.
Also, in the specification of Japanese Patent Laid-Open Application No. 2-121845, a method for processing the grooves that constitute ink paths is introduced for an ink jet recording head structured by bonding a ceiling plate, which is provided with the recessed portions to form ink paths arranged corresponding to each of a plurality of discharge openings, as well as a common liquid chamber that retains ink to be supplied to the ink paths, together with a substrate having discharge energy generating devices arrange on a part of each of the ink paths. In this method, the ceiling plate having the grooves to form the common liquid chamber is produced by means of an injection molding, and then, the ink paths are formed by the irradiation of excimer laser on the ceiling plate thus produced.
However, in recent years, there have been more demands on higher precision as image quality along with the wider use of digital cameras or the like. In order to meet such demand on the image quality that requires higher precision, the density of ink flow paths should be arranged to be as high as 600 DPI (the pitches of ink flow paths being 42.375 .mu.m) or more. However, in accordance with the method for forming the ink flow paths by means of injection molding, which is disclosed in the Japanese Patent Laid-Open Application No. 55-132253, the production yield should be extremely lowered if this method is adopted for manufacturing heads having such higher density of flow paths as compared with the heads conventionally in use. Here, the problems are encountered, such as defective flow-in of resin into the metallic mold, and the chips that may be present at the time of mold releasing to make the product defective. Also, regarding the method for forming ink flow paths by the irradiation of excimer laser, which is disclosed in the Japanese Patent Laid-Open Application No. 2-121845, the region of laser irradiation should be increased in order to meet the demand on the higher density of ink flow path arrangement. This requirement results in the heat accumulation on the ceiling plate more than conventionally accumulated on it, which inevitably leads to the expansion of the work. At the same time, with the higher arrangement of ink flow paths thus required, allowable errors become smaller so that it is made difficult to stabilize the formation of ink flow paths in a desired precision.
As described above, therefore, there is a need for the provision of a method for manufacturing ink jet recording head, which is capable of forming the ink flow paths in a desired precision stably when the ink flow paths should be arranged in a density of as high as 600 DPI or more, for example.